Not applicable.
1. Field of the Invention
The present invention relates to screening patients to determine their risk for having major depression.
2. Description of the Related Art
A bibliography follows at the end of the Detailed Description of the Invention. The listed references are all incorporated herein by reference.
The lifetime frequency of major depression (MD) is twice as high in women as in men (1). Twin studies have shown a significant genetic contribution to MD in women with heritabilities ranging from 0.33 to 0.45 and higher (2-5), and an important role of stress (6). Some twin studies have suggested a comparible heritability for men and women (4), while others have suggested a greater heritability for women (5). In 1972 and again in 1994, Janowsky (8, 9) reviewed the evidence for a role of cholinergic hypersensitivity in depression. Both REM and non-REM sleep is regulated by cholinergic, serotonergic and noradrenergic neurons in the brain stem (10). The early onset of REM sleep, increased REM density and exaggerated REM response to cholinergic stimulation in depression, is consistent with CNS cholinergic overactivity or muscarinic supersensivity in depression (10). While the HPA axis has been emphasized in the response to stress, recent studies of Kaufer, et al. (11) have identified an important alternative cholinergic pathway. They showed that acute stress resulted in an immediate increase in synaptosomal acetylcholine with neuronal excitability, with a delayed phase response of increased expression of acetylcholineaserase, decreased choline acetyl transferase and vesicular acetylcholine transporter (CHAT) activity and a resulting decrease in neuronal excitability (11, 12). Others have also emphasized the important role of stress in activating muscarinic systems (13).
In one aspect, the present invention relates to a method for screening a patient to determine whether such patient is at increased risk for developing major depression, said method comprising analyzing a sample of said patient""s genetic material to determine the patient""s genotype with respect to the cholinergic muscarinic receptor 2 (CHRM2) gene, wherein the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of said gene correlates with an increased risk for developing major depression.
In another aspect, the present invention relates to a method for diagnosing major depression in a patient, said method comprising analyzing a sample of a patient""s genetic material to determine to determine the patient""s genotype with respect to the cholinergic muscarinic receptor 2 (CHRM2) gene, wherein the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of said gene is indicative of the presence of major depression.
In another aspect, the present invention relates to a method for screening a subject to determine whether such subject is a candidate for a therapy using a drug which prevents or treats a disorder associated with the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of the cholinergic muscarinic receptor 2 (CHRM2) gene, said method comprising determining the subject""s genotype with respect to such gene, wherein a subject having a T at said nucleotide number is a candidate for such therapy.
In another aspect, the present invention relates to a method for treating a patient having or at increased risk for developing major depression associated with the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of the cholinergic muscarinic receptor 2 (CHRM2) gene, said method comprising administering to said patient an effective amount of a material which diminishes the effect of such gene.
In another aspect, the present invention relates to a method for identifying materials that can be used in the treatment of a patient having or at increased risk for developing a disorder associated with the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of the cholinergic muscarinic receptor 2 (CHRM2) gene, said method comprising determining whether the material is capable of diminishing the effect of such gene.
In another aspect, the present invention relates to a pharmaceutical composition which comprises
a) an effective amount of a material which is capable of diminishing the effect of the cholinergic muscarinic receptor 2 (CHRM2) gene having a T at nucleotide number 1890 in the 3xe2x80x2 UTR; and
b) a pharmaceutically acceptable carrier.
In another aspect, the present invention relates to a kit suitable for screening a subject to determine whether such subject is at increased risk for having or developing a disorder associated with the presence of a T at nucleotide number 1890 in the 3xe2x80x2 UTR of the cholinergic muscarinic receptor 2 (CHRM2) gene, said kit comprising
a) material for determining the subject""s genotype with respect to said gene;
b) suitable packaging material; and optionally
c) instructional material for use of said kit.
The present invention is based on the observation that subjects, particularly females, having a T at nucleotide number 1890 in the 3xe2x80x2 UTR of the cholinergic muscarinic receptor 2 (CHRM2) gene have an increased risk of having major depression.
The present invention entails the determination of the subject""s genotype with respect to the CHRM2 gene. That gene is located on chromosome 7q31-q35. See reference (23) and the references cited therein, the contents of which are incorporated herein by reference. The relevant portion of the sequence is as follows (the T nucleotide at position 1890 is indicated in bold type): acatgggaat taggcaggta gacacagtaa tcatgcaggg gaagggagat 50 ttgggagaaa ataatgtggt ttaaaaggag aaacaacatt atgtatttta 100 aaccaatgtt tatattatgt ttgttaattt tattctattt ccttgcaggt 150 ttaaatgttt atttgctact tggctactga ttagagaacg caaaatgaat 200 aactcaacaa actcctctaa caatagcctg gctcttacaa gtccttataa 250 gacatttgaa gtggtgttta ttgtcctggt ggctggatcc ctcagtttgg 300 tgaccattat cgggaacatc ctagtcatgg tttccattaa agtcaaccgc 350 cacctccaga ccgtcaacaa ttacttttta ttcagcttgg cctgtgctga 400 ccttatcata ggtgttttct ccatgaactt gtacaccctc tacactgtga 450 ttggttactg gcctttggga cctgtggtgt gtgacctttg gctagccctg 500 gactatgtgg tcagcaatgc ctcagttatg aatctgctca tcatcagctt 550 tgacaggtac ttctgtgtca caaaacctct gacctaccca gtcaagcgga 600 ccacaaaaat ggcaggtatg atgattgcag ctgcctgggt cctctctttc 650 atcctctggg ctccagccat tctcttctgg cagttcattg taggggtgag 700 aactgtggag gatggggagt gctacattca gtttttttcc aatgctgctg 750 tcacctttgg tacggctatt gcagccttct atttgccagt gatcatcatg 800 actgtgctat attggcacat atcccgagcc agcaagagca ggataaagaa 850 ggacaagaag gagcctgttg ccaaccaaga ccccgtttct ccaagtctgg 900 tacaaggaag gatagtgaag ccaaacaata acaacatgcc cagcagtgac 950 gatggcctgg agcacaacaa aatccagaat ggcaaagccc ccagggatcc 1000 tgtgactgaa aactgtgttc agggagagga gaaggagagc tccaatgact 1050 ccacctcagt cagtgctgtt gcctctaata tgagagatga tgaaataacc 1100 caggatgaaa acacagtttc cacttccctg ggccattcca aagatgagaa 1150 ctctaagcaa acatgcatca gaattggcac caagacccca aaaagtgact 1200 catgtacccc aactaatacc accgtggagg tagtggggtc ttcaggtcag 1250 aatggagatg aaaagcagaa tattgtagcc cgcaagattg tgaagatgac 1300 taagcagcct gcaaaaaaga agcctcctcc ttcccgggaa aagaaagtca 1350 ccaggacaat cttggctatt ctgttggctt tcatcatcac ttgggcccca 1400 tacaatgtca tggtgctcat taacaccttt tgtgcacctt gcatccccaa 1450 cactgtgtgg acaattggtt actggctttg ttacatcaac agcactatca 1500 accctgcctg ctatgcactt tgcaatgcca ccttcaagaa gacctttaaa 1550 caccttctca tgtgtcatta taagaacata ggcgctacaa ggtaaaatat 1600 ctttgaaaaa gatagaaggt gggcaagggg agcttgagaa gaataaaagg 1650 gataaacgag ctcctagttt taaaatctct gccattgcac tttatagtct 1700 gattacaaaa cgtgcaattc aggagcccag cagtgacaca cttatcacgc 1750 ctaggctcca gtttgcaaaa attgcacctt ataaactgtc agtattagga 1800 gcaatgagac aatgaaagaa acatgttggg atcgtggatt taagaaacta 1850 tacactgttt ctcataatct cttgaagaag ggcttctgat tctacaattt 1900 tatcagtctc tgcacaagag gaataacctt gttccttttt tgttactttt 1950 gttgttgttg ttctcatgtg tccttaagag aaggaatgcc acagttacaa 2000 ggtaaacatg gagacttaaa cataaagaaa taggcactat acaatgggga 2050 cataaaaaaa gaaaatgaaa gaaggatgca gaaatttgtc tccggagtgt 2100 taagcatatt ttattctttt gttacggtcc tatttagagg attggaatgt 2150 aataaatgct tattttttgc ctttcttttt cccaccatga agagaaagca 2200 aacaaacaga 2210 [SEQ ID NO:1].
Such can be determined, for example, by analysis of the subject""s DNA. Suitable analysis techniques are well known to those in the art, and include amplification genotyping (amplification of the desired region by suitable methods, such as PCR, followed by electrophoresis), in situ hybridization techniques, direct DNA sequencing, etc.
A further aspect of the present invention is the treatment of a disorder associated with the presence of the allele described herein, to prevent the development or progression of such disorder. The patient is administered an effective amount of a material which diminishes or eliminates the adverse effects of the allele. The material may act in a number of ways which would be apparent to one of ordinary skill. For example, it may act to decrease the production of the protein, such as by affecting the DNA or RNA responsible for protein production, or by affecting regulatory elements. One way to accomplish diminished protein production is by introduction via gene therapy or gene repair techniques of a gene or gene segment which converts the allele associated with the disorder into a benign allele. See, for example, the techniques described in U.S. Pat. No. 5,776,744, the contents of which are incorporated herein by reference. The material may also act by directly or indirectly affecting the produced protein to diminish the protein""s activity or effect.
It will be apparent that the information regarding a subject""s genotype with respect to the CHRM2 gene may also be used to determine whether the subject is a candidate for a therapy using a drug which prevents or treats a disorder associated with the CHRM2 gene in question.
For therapeutic treatment, the materials of the present invention may be formulated into a pharmaceutical composition, which may include, in addition to an effective amount of the active ingredient, pharmaceutically acceptable carriers, diluents, buffers, preservatives, surface active agents, and the like. Compositions may also include one or more other active ingredients if necessary or desirable.
The pharmaceutical compositions of the present invention may be administered in a number of ways as will be apparent to one of ordinary skill in the art. Administration may be done topically, orally, by inhalation, or parenterally, for example.
Topical formulations may include ointments, lotions, creams, gels, drops, suppositories, sprays, liquids and powders. Oral formulations include powders, granules, suspensions or solution in water or non-aqueous media, capsules or tablets, for example. Thickeners, flavorings, diluents, emulsifiers, dispersing aids or binders may be used as needed.
Parenteral formulations may include sterile aqueous solutions which may also contain buffers, diluents and other suitable additives.
The dose regimen of the compounds or compositions of the present invention will depend on a number of factors which may readily be determined, such as severity and responsiveness of the condition to be treated.
The present invention also provides a screening method for identifying materials that may be used in the treatment of a patient having or at increased risk for developing a disorder associated with the presence of the CHRM2 gene having a T at nucleotide number 1890 in the 3xe2x80x2 UTR. In practice of such a method, a candidate material is screened in an assay which determines whether the material is capable of diminishing the effect of the gene in question. Suitable assays would be readily apparent to one of ordinary skill, including animal models and in vitro assays. The assays may be designed to test, for example, the effect of the material on the production of the particular protein, or its effect on the activity of the protein.
The present invention also provides a kit suitable for screening a subject for any of the purposes described above. The kit comprises material for determining the subject""s genotype with respect to the CHRM2 gene. Preferably, such material comprises at least two primers capable of hybridizing to a region flanking nucleotide number 1890 in the 3xe2x80x2 UTR segment of the CHRM2 gene. The primers preferably are suitable for use in an amplification reaction, such as PCR. The kit additionally contains suitable packaging material, and optionally contains instructional material for use of the kit, result interpretation, etc. The kit may also contain additional reactants suitable for use with the primers, such as appropriate concentrations of deoxynucleotide triphosphates, suitable buffers, polymerization enzymes, etc.
The following non-limiting examples are illustrative of the processes and products of the present invention.